Monday, July 30, 2007 - 8:00 AM
S29
Feasibility of an in situ measurement device for bubble size distributions
Beth Junker1, Waldemar Maciejak1, Branson Darnell2, Michael Lester1, and Michael Pollack2. (1) Merck & Co., Inc, RY810-126, PO Box 2000, Rahway, NJ 07065-0900, (2) Environoptics, Colmar, PA
The feasibility of in situ measurement device for bubble size distributions was explored. A novel in situ probe measurement system, the EnviroCamTM, was developed. Where possible, this probe incorporated strengths, and minimized weaknesses of historical and currently-available real-time measurement methods for bubbles and pellets/mycelia. The system was based on a digital, high-speed, high resolution, modular camera system, attached to a stainless steel shroud, compatible with standard Ingold ports on fermenters. Still frames and/or video were produced, capturing bubbles passing through the notch of the shroud. The light source, an LED, was integral with the shroud. Bubbles were analyzed using customized commercially-available image analysis software and standard statistical methods. Using this system, bubble sizes were measured as a function of various operating parameters (e.g., agitation rate, aeration rate) and as a function of media properties (e.g., viscosity, antifoam, cottonseed flour, and microbial/animal cell broths) to demonstrate system performance and its limitations.